ARGENTINA is a vast country. In length, it covers the same distance as Gibraltar to John O'Groats, and you could pop all of the European Economic Community into its boundaries. The high deserts in the northwest glow peculiar hues because of the minerals buried there, and many of the mountains, sliced like geographical models by erosion, reveal streaks coloured like angel-cake. The southern regions have wide, empty lakes, where cowboys are often found tending rawhide-size herds of cattle, albeit often by jeep, rather than horse. It is to Buenos Aires, however, that most visitors come and, for first-timers, it is a revelation: the city is one of great beauty, with wide boulevards, graceful squares, classical buildings, and pavement cafes which long ago earned the justified sobriquet, ''The Paris of Latin America''. The city, which was originally founded in 1536, grew up in a neat Spanish pattern on the wide, flat land. The enormous prosperity of the 1880s meant a tremendous flourishing of architecture, and the modern shape of the city is still based very much on those times. The visitor will find Spanish-style government buildings, French-style villas and British-style railway stations. But it isn't just the physical attractions of Buenos Aires which draws visitors there. There are two people who in their own way have left an indelible mark on the city: Jorge Luis Borges and Evita Peron. Borges, who died in 1986, was born into one of Buenos Aires' old patrician families. Although he started going blind in the 1920s, his works helped to define an image of the city which is at once real and hopelessly romantic. Palermo is the place to go looking for the Buenos Aires of Jorge Borges, a network of European streets wedged in behind the boulevards. Here is the botanical gardens and the zoo, which Borges described as smelling ''of caramel and tiger''. Here, too, the visitor will find the grand Monumento de Los Espanoles, and the house of Brigadier Juan Manuel de Rosas, ''a fat, blonde man who walked the clean pavements'', and who is another part of Palermo mythology. Perhaps best of all, Palermo is renowned for its little bookshops and its pavement cafes, and here, too, is the place to seek out the tango, that steamy, insidious music, which originated in the cheap bars where gangsters and their girls ruled and where the sons of good families gravitated in their fascination with the low life. The result of this rich brew was a music which titillated the world. Palermo is the place to go, too, for those in search of Evita Peron. Up against the walls of Palermo washes the Recoleta, the city's most glamorous necropolis - for, if Argentinians lead life to the full, they live death to the full, too. Walking through an imposing archway, you will find yourself in what can only be described as a township of tiny, perfect mansions. The mausoleums stand, closely packed, along narrow, hushed streets. Grand steps lead up to the solemn front doors, next to which the family name-plate has properly been fixed. Many of the doors have glass panels, showing pleasant little lobbies, tiled floors, steps leading down into the vault, and even, on occasions, the magnificent brass-handled coffins. The burial site of Evita is hard to find, partly because she lies in her own family tomb, that of the Durate family. The side turning is small and unremarkable, and the only thing which really distinguishes the tiny villa as the final resting place of one of the nation's most charismatic figures is a small embossed name plate by the door. That and the occasional flower pushed into the iron grille by an admirer.